The Monatron package

An extensible monad transformer library with uniform liftings, a
fairly portable core, and option of explicit naming of liftings.
See http://www.fceia.unr.edu.ar/~mjj/Monatron/ for more information.
The monad zipper allows modular composition of components with Monatron effects.
It is a contribution of Bruno Oliveira and Tom Schrijvers.
See http://www.cs.kuleuven.be/~toms/Haskell/ for more information.